Pattern matching servant client functions out of generic record

Demo.hs

module PI.Demo where

import Servant (Handler, Put)
import Servant.API.Generic (AsApi, ToServant, fromServant)
import Servant.Client (ClientM)
import Servant.Client.Generic (AsClientT, genericClient)
import Servant.Server.Generic (AsServer, genericServer)

data Parent mode = Parent
    { parent1 :: mode :- Capture "x" Int :> Get '[JSON] String
    , parent2 :: mode :- ToServant Child AsApi
    } deriving (Generic)

data Child mode = Child
    { child1 :: mode :- Capture "x" Int :> Get '[JSON] String
    , child2 :: mode :- ReqBody '[JSON] Int :> Put '[JSON] Bool
    } deriving (Generic)

type ParentChildApi = Parent AsApi
type ParentChildServer = ToServant Parent AsServer
type ParentChildClient = Parent (AsClientT ClientM)

demoServer :: ParentChildServer
demoServer = genericServer $ Parent
    { parent1 = undefined :: Int -> Handler String
    , parent2 = genericServer $ Child
        { child1 = undefined :: Int -> Handler String
        , child2 = undefined :: Int -> Handler Bool
        }
    }

callParent1 :: Int -> ClientM String
callParent2Child1 :: Int -> ClientM String
callParent2Child2 :: Int -> ClientM Bool
Parent
    { parent1 = callParent1
    , parent2 = fromServant @Child @(AsClientT ClientM) -> Child
        { child1 = callParent2Child1
        , child2 =  callParent2Child2
        }
    } = genericClient